Thank you Alex
I began with SBI's Block Builder, but found it a little clunky and time consuming. So I took the next step recommended by SBI and switched to the Upload Your Own HTML function. This is still a part of SBI, and I don't need any other software but a HTML Editor. (I use DreamWeaver, but you can download a free editor online, such as Ace HTML.)
So, although I had an SBI template to start with, I convinced my partner to make me some unique graphics, and put those into DreamWeaver. Now I write every page from the same template, in Preview Mode. That's the beauty of a WYSIWYG editor (What You See It What You Get). You hardly need to know any HTML!
I then upload each page to SBI, which gives me the chance to Preview and Analyze it before I build it. This is much like the Block Builder function, and a very useful tool. If you are interested in learning more about the Upload Your Own HTML function, read SBI's Transition Guide (an add-on feature in Day 6 of the Guide).
Thanks for the lovely feedback on my design - my partner will be happy to hear it! He is offering his design skills to other SBIers for a special rate, so if you want to make the transition to HTML one day in future, let us know.

However Alex I must say you have a great, clean looking SBI template and you have nothing to worry about!